NiCrAlFe精密电阻合金中的L12有序结构研究  

L12-Type Ordered Structures in NiCrAlFe Precision Resistance Alloy

作　　者：黄树东 王勇[1] 杨贤军 徐永红 Huang Shudong;Wang Yong;Yang Xianjun;Xu Yonghong(College of Materials Science&Engineering,International Joint Laboratory for Light Alloys,Ministry of Education,Chongqing University,Chongqing 400044,China;Chongqing Chuanyi Metallic Functional Materials Co.,Ltd,Chongqing 400702,China)

机构地区：[1]重庆大学材料科学与工程学院教育部轻合金材料国际合作联合实验室,重庆400044 [2]重庆川仪自动化股份有限公司金属功能材料分公司,重庆400702

出　　处：《稀有金属材料与工程》2020年第12期4159-4165,共7页Rare Metal Materials and Engineering

基　　金：国家重点研发计划(2016YFB0402603)。

摘　　要：利用第一性原理赝势平面波方法,计算了NiCrAlFe合金处于无序固溶体结构和形成L12型有序结构时的结合能、态密度、晶格常数等参数,并利用高分辨透射电子显微镜(HRTEM)对合金进行了结构表征,还测试了固溶态和时效态的电阻率。从结合能来看,该合金形成L12有序结构时比无序固溶体更加稳定;态密度以及部分态密度计算结果则表明,在L12有序结构中,Ni、Cr、Al、Fe会强烈成键而使得整个合金体系变得稳定;HRTEM分析结果证明固溶态合金经过时效处理后出现了L12有序结构,而且该有序结构的晶格常数与计算值基本一致。对比无序固溶体与L12型有序结构费米能级处的态密度值发现,当形成L12有序结构时合金的导电能力较无序固溶体下降,电阻率升高,与实际测试结果吻合。Using the first-principles pseudopotential plane-wave method,the binding energies,density of states and lattice constants of a NiCrAlFe precision resistance alloy were calculated based on the disordered solid solution and L12-type ordered structures.The microstructure of the alloy was analyzed by high-resolution transmission electron microscope(HRTEM).Also,the electrical resistance of the alloy was measured after solid-solution and aging treatment.From the binding energy point of view,the L12-type ordered structure is more stable than the disordered solid solution structure.The calculation results of density of states and partial density of states show that in the L12-type ordered structure,Ni,Cr,Al and Fe atoms bond with each other more strongly than they do in the disordered solid solution structure.Thus the stability of the alloy is improved.In fact,L12-type ordered structure is revealed by HRTEM in the as-aged alloy,and its lattice parameters are close to the calculated results.According to the comparison of density of states at the Fermi level o f different structures,the electrical conductivity of the alloy decreases due to the formation of L12-type ordered structure compared with that of the disordered solid solution structure,which is consistent with the experimental results.

关 键 词：精密电阻合金 第一性原理 高分辨透射电镜 L12有序结构 无序固溶体 

分 类 号：TG146.1[一般工业技术—材料科学与工程]